The U.S. Department of State (DoS) has requested window glazings for secure facilities, to provide radio frequency (RF) and infrared (IR) attenuating glazing solutions in an attempt to prevent electromagnetic signals from emanating from secure government facilities in order to prevent eavesdropping and reduce the transmission of confidential information from the interiors of such buildings. The current approach to achieve this is either through the application of aftermarket window film products that incorporate proprietary materials to provide the required attenuation, or a monolithically laminated glazing having two substrates with a polyvinyl butyral (PVB) or SGP laminating interliner with mechanically deposited materials on surface #2 and surface #3 (i.e., on the surfaces of the substrates that face the interliner). Such approaches are costly, difficult to manufacture/implement, and sometimes provide for inadequate signal blockage.
In certain example embodiments of this invention, there is provided a window for attenuating (e.g., blocking, such as reflecting and/or absorbing) significant amounts of radio frequency (RF) and infrared (IR) electromagnetic signals, so as to prevent or reduce such signals from emanating from secure facilities (e.g., government and/or military facilities). Example embodiments of this invention provide for a window including at least first and second glass substrates, at least first and second low-emissivity (low-E) coatings for blocking at least some IR and RF signals, and at least one transparent conductive oxide (TCO) inclusive coating for blocking at least some RF signals. The TCO inclusive coating may include a layer of or including indium-tin-oxide (ITO) located between at least a first dielectric layer of or including silicon oxynitride and a second dielectric layer of or including silicon oxide, silicon nitride and/or silicon oxynitride. The TCO inclusive coating can be located on the innermost glass substrate so as to face the building interior, in order to improve RF/IR attenuation at least at a central area of the window. Moreover, the TCO inclusive coating is durable and does not require edge deletion. Thus, in embodiments where the low-E coating(s) is/are edge deleted (i.e., removed from the substrate proximate at least one edge thereof), but the RF blocking TCO inclusive coating is not edge deleted, the non-edge deleted TCO inclusive coating allows for electrical termination to a conductive window frame along all sides of the window in order to eliminate or reduce waveguide leakage of RF proximate the periphery of the window.
In certain example embodiments of this invention, there is provided a window structure comprising: first and second glass substrates that are laminated to each other via a polymer-based laminating layer; a first low-E coating on a first major surface of the first glass substrate; a second low-E coating on a first major surface of the second glass substrate, wherein the first and second low-E coatings face each other with no glass substrate therebetween; wherein each of the first and second low-E coatings comprises at least two IR reflecting layers comprising silver that are spaced apart from one another via at least one dielectric layer; an RF blocking coating on a second major surface of the second glass substrate for facing an interior of a building in which the window structure is to be mounted, and wherein the RF blocking coating comprises a transparent conductive layer comprising indium-tin-oxide (ITO) that is located between first and second dielectric layers; wherein the first low-E coating is edge deleted so that the first low-E coating is not present on the first major surface of the first glass substrate along an edge of the first glass substrate; wherein the second low-E coating is edge deleted so that the second low-E coating is not present on the first major surface of the second glass substrate along an edge of the second glass substrate; and wherein the RF blocking coating is not edge deleted, so that the RF blocking coating is present across the entire second major surface of the second glass substrate.
In certain example embodiments of this invention, there is provided a window structure comprising: first and second glass substrates that are laminated to each other via a polymer-based laminating layer; a first low-E coating on a first major surface of the first glass substrate, so that the first low-E coating faces the second glass substrate with no glass substrate therebetween, and wherein the first low-E coating comprises at least two IR reflecting layers comprising silver that are spaced apart from one another via at least one dielectric layer; an RF blocking coating facing an interior of a building in which the window structure is mounted, and wherein the RF blocking coating comprises a transparent conductive oxide layer that is located between first and second dielectric layers; wherein the first low-E coating is edge deleted so that the first low-E coating is not present on the first major surface of the first glass substrate along at least one edge of the first glass substrate; and wherein the RF blocking coating is not edge deleted.